The conventional incandescent light bulb has an external right hand threaded base and is threaded into a mating socket. The bulb can be removed by simply reversing it or screwing it out of the socket. This type of bulb and socket is so universally used that a bulb removed from one socket can be used in almost any other socket anywhere.
In many places the theft of light bulbs is a substantial and continuing problem. This is especially true in hotels, motels, apartment buildings and the like. The cost of replacing stolen bulbs is often substantial, including both the cost of bulbs and labor for replacing them. In addition, the theft of a bulb may result in a hazardous condition for customers, tenants or guests where a bulb is removed over a stairway or near some obstacle. At best, a stolen bulb results in an inconvenience. There is a longstanding need for a simple and inexpensive way to deter stealing of bulbs.